The explorers who set out two hundred years ago were in danger for three years. Their legacy was in danger for decade after decade—and it was Meriwether Lewis who almost killed it.

It was nearly a century before the public could read what Lewis and Clark wrote.

Gass’s publication ought to have galvanized Lewis into making extra efforts to get his own book out, and he did arrange with a Philadelphia publisher, John Conrad, to print it. He sat for Charles Willson Peale for his portrait. He arranged with a man named Frederick Pursh, a German naturalist living in Philadelphia, to make drawings of the plants he had brought back and paid him $70 in advance. He met Alexander Wilson, the ornithologist, and asked him to make drawings of some of the birds discovered on the expedition, and Wilson did. Lewis ran a few personal errands for Jefferson. He worked on the expedition’s accounts. He went to dinners and to balls. He courted someone we know only as Miss A-n R—h, who refused him.

But he seems not to have written a single word of his book. Stephen Ambrose, in Undaunted Courage , suggests that Lewis was drinking too much and was on the path to alcoholism. Richard Dillon, Lewis’s biographer, is more reluctant to explain the delay. It is not entirely certain in any case where Lewis was from the summer of 1807 to the early spring of 1808, when he finally arrived, a year late, to take up his duties in St. Louis as governor of the territory. Wherever Lewis was, whatever he was doing, he was not preparing the journals for publication.

In St. Louis at last, Lewis fell into a hornets’ nest of bickering and backbiting. His second-in-command, a man named Frederick Bates, turned out to be his enemy and undercut him at every turn. The U.S. military commander in the area was Gen. James Wilkinson, in whom Jefferson placed great trust but who was in fact a spy on the payroll of the Spanish government.

Dealing with still unsettled affairs of the expedition while trying to adjudicate between the various factions in St. Louis —between new American settlers and the entrenched French, between fur traders and farmers, the usages and their enemies the Sauks, must have taken most of his time. To make matters worse, Lewis had few skills as an administrator. He was a military man, a superb leader, but not adaptable, not subtle, not political . The pressures on him were intense, and he was not fitted for them. They left him no time to write, and he did not write. He did not even reply to Jefferson’s increasingly anxious letters. This was odd, almost unforgivable. Thomas Jefferson was not only his friend but the President of the United States, and he, Meriwether Lewis, was a governor. He was supposed to keep the President up to date on the affairs of Upper Louisiana. But he did not write.

When Clark heard of Lewis’s death, he wrote “I fear O!...What will become of his paprs?”

Matters came to a head in the spring of 1809, when the War Department authorized Lewis to pay $7,000 to Pierre Choteau, one of the leading figures in the fur trade in St. Louis, to conduct a mission into Indian territories. Lewis added $500 to this amount on his own authority for gifts to the tribes. Lewis was used to doing this; he was always personally in debt and had spent many thousands of dollars more outfitting the Corps of Discovery than he was authorized to spend. But Jefferson was no longer President, and the new Secretary of War wrote Lewis a sharp letter questioning what he had done. Lewis thought his honor had been impeached. “I have been informed,” he wrote to the new Secretary of War, William Eustis, “Representations have been made against me.” He referred to the traitor Aaron Burr: “Be assured Sir,” he wrote indignantly, “that my Country can never make ‘A Burr’ of me—She may reduce me to Poverty, but she can never sever my Attachment from her.” Early in September, determined to prove his innocence, he left St. Louis for Washington. He planned at first to go by way of New Orleans but opted instead to move overland through Tennessee. He wrote ahead to President James Madison, to alert him to his pending arrival, and told him he was bringing all his invoices plus “the original papers relative to my voyage to the Pacific ocean.”

In late September he left Fort Pickering, on the Mississippi, for Washington, in the company of a man named James Neelly, an Indian agent to the Chickasaws. In a letter to Jefferson dated October 18, Neelly said that he found Lewis “at times deranged in mind.” On the way they lost two of their horses, and Neelly stayed behind to look for them. Lewis told him he would wait for him at the first house inhabited by white people. He arrived at the door of a Mr. Grinder and took lodgings there. “The man of the house being from home, and no person there but a woman who discovering the governor to be deranged, gave him up the house & slept herself in one near it.” About three in the morning she heard two pistol shots. Lewis was still alive when she went into his room, but it was too late to save him. He had killed himself. Two years later, after an investigation into the circumstances, the last person to see him alive, a young boy, quoted Lewis as saying that he had killed himself “to deprive his enemies of the pleasure and honor of doing it.”